There are no proscriptions against public prayer in the US. If a group of people wanted to go into a public park and pray, loudly, they would be permitted as long as they are not interfering with other people's activities. Personally, I have no objection to this activity, provided it is available to ALL who want to pray. Including Christians, Jews, Muslims or any other religious group.
One thing that has happened in several communities around the US is that Christians, who have frequently performed prayer meetings similar to this, have tried to prevent those of other faiths from enjoying the same rights. To the point where the city government has had to restrict ALL faiths, including Christians, from using the park just so that the Christians can prevent OTHERS from using it. I also recall a case back in 2002 where a Christian community complained about the local mosque issuing their call to prayer, through loudspeakers, five times a day. Claiming it was a disturbance. Wound up that the city had to ban the use of Church bells on Sundays in order to stop the mosque. Not exactly the result the Christians wanted!
I have no problem with it either. Many businesses make allowances for such things. But that Muslim is not forcing a public meeting to begin with a prayer, the way that many Christian communities do.Mostly I agree. But I would have no problem with for instance a muslim doing his or her praying on a little carpet in the corner of a room 5 times a day, or someone praying quietly somewhere, if there is no prayer room.